LIMB PROTECTOR

Abstract: A limb protector to protect a knee or elbow joint in active sports and also for use after the joint has been injured has upper and lower curved, rigid, resilient supports which can be attached to an arm or leg above and below the knee or elbow, is arranged so that the upper and lower supports can rotate relative to each other, by an adjustable amount, in a horizontal plane and can also hinge relative to each other in a vertical plane.

Description: "Limb Protector" This invention relates to a limb protector, particularly a protector for a jointed limb, that is a knee or elbow protector. Injuries to limbs and to joints occur for several reasons, including participation in contact sports such as American football or ice hockey, in individual sports such as skiing or motor cycle racing, or indeed any active sport. In addition, injuries to limbs and joints occur in active occupations such as the police or armed forces, or in any type of accident. After an injury occurs, the limb or joint affected by a minor injury is conventionally supported by elastic supports which give slight restriction of movement or by rigid splints for major injuries, giving complete immobilization. In some cases, preventative equipment if available. Hinged knee braces (de-rotational braces) are available to prevent twisting of a knee, and can be worn during activities such as skiing, but by their nature are restrictive, the hinges permit only forward bending. Braces are available for sports such as American football which protect the knee against side impact, or frontal impact, but also restrict movement, (prophylactic or preventive braces) . Dynamic braces are also available, with eccentrically placed hinges to provide protection to torn ligaments. In more extreme form, riot police can wear body armour. In a different sphere, the medical profession use light weight splints to give complete immobilization of a knee or elbow when rotational movement is likely to cause damage, especially for use in accidents to permit safe transport of the person to hospital. In many cases, a small amount of movement of the affected joint might be beneficial to healing, and indeed speed recovery, but existing equipment allows either relatively large twisting movements, as with elastic supports, or no twisting movement, as with hinged braces. The current invention provides a broader range of facilities than any existing brace, and can be used in prophylactic, dynamic, or de-rotational mode. According to the invention a limb protector comprises an upper rigid curved support; a lower rigid curved support; and means for permitting relative rotation of the upper support and the lower support. Preferably the relative rotation takes place in a plane substantially parallel to the planes of curvature of the upper and lower supports, and preferably the amount of relative rotation is adjustable. Preferably there is also provided means for permitting relative hinging of the upper and lower supports in a plane orthogonal to the plane of relative rotation. In use the upper rigid curved support is placed around the upper part of a limb, such as a thigh or upper arm, and the lower rigid curved support is placed around the lower part of a limb, such as a lower leg or forearm. The means permitting relative hinging of the supports permits the knee or elbow to bend in a plane which in the case of the knee will be substantially vertical with the relative rotation being in a substantially horizontal plane, permitting the knee to twist, to a degree which can be preset. Preferably there is also provided a rigid curved direct impact protector which overlaps the lower portion of the upper support and the upper portion of the lower support. The direct impact protector protects a knee joint from front impact and an elbow joint from rear impact. Optionally there is further provided at least one rigid side impact protector, overlapping the lower portion of the upper support and the upper portion of the lower support and positioned to protect a joint within the supports from side impact. Preferably the rigid material of which the curved supports are made is resistant material such as carbon- fibre reinforced plastics material. The invention will now be described by way of example only with reference to the accompanying drawing in which: Figure 1 is an exploded view of a knee protector according to the invention; Figure 2 is a detailed view of part of Figure 1 illustrating the relative rotation of the upper and lower limb supports at the front of the support; Figure 3 is a detailed view of part of Figure 2; Figure 4 is a detailed view of a further part of Figure 1 illustrating the relative rotation of the upper and lower limb supports at the rear of the support; Figure 5 is a view of an assembled, alternative embodiment of a knee protector according to the invention; Figure 6 is an example of an adjustable fastening mechanism for a limb protector; Figure 7 is an example of means for adjusting the size of a knee protector for width fitting; Figure 8 illustrates means for allowing hinging movement; Figure 9 is an example of a wall material; Figure 10 illustrates the knee protection of Figure 1 in assembled form; Figure 11 illustrates how hinging action allows the protector to be put on a human knee; Figure 12 illustrates a variation of the protector of Figure 1; Figure 13 illustrates the protector of Figure 1 from in front and from the rear; Figure 14 is a variation of the protector illustrated in Figure 1; Figure 15 is a view of the inside of the Figure 14 embodi ent; Figure 16 shows the assembly of the Figure 1 variation; Figure 17 illustrates a variation of Figure 14. In Figure 1 a knee protector comprises an upper frontal leg support 10, a lower frontal leg support 12, an upper rear leg support 14 and a lower rear leg support 16. Each leg support 10, 12, 14, 16 is curved to fit a human leg (not shown) and conveniently made of rigid but resilient material. Each leg support may be of greater length in the vertical direction than illustrated, to give increased leg support and protection. The lower part of upper frontal leg support 10 and the upper part of lower frontal leg support 12 are provided with extensions 18, 20 respectively of gradually increasing curvature, or skirt-shaped parts, to accommodate the human kneecap. The gap between the edges of the extensions 18, 20 is covered by a curved knee protector 22 which extends around the upper and lower frontal supports. The knee protector protects the knee from impacts from the front, and the overall arrangement prevents the knee from being pushed backwards, as the upper and lower supports distribute the impact to the tibia and fibia. The leg supports 10, 12, 14, 16 and the knee protector 22 are connected together to allow the knee joint to bend in a vertical plane, ie to bend normally. Conveniently this is achieved by connecting studs (not shown) which pass through apertures in the aforementioned parts. For example, one stud could pass through the circular aperture 24 in upper rear support 14, circular aperture 26 in upper frontal support 10 and circular aperture 28 in the side upper part of knee protector 22. Another stud could pass through circular aperture 30 in lower rear support 16, circular aperture 32 in lower frontal support 12 and kidney-shaped aperture 34 in the side, lower part of knee protector 22. A similar arrangement of apertures and studs is provided on the side of the protector distant from the direction of viewing. Such an arrangement will allow normal bending of the knee, with the stud moving along kidney-shaped aperture 34. Preferably this aperture is provided with ball bearings in a retaining channel, as shown by references 36, 38 in the partial enlargement. There is also provided a circular side impact protector 40, of rigid, resilient material provided with an upper circular aperture 42 and a lower kidney-shaped aperture 44 through which studs can pass as through corresponding apertures in the side of the protector distant from the direction of viewing. The studs would hold the side impact protector 40 in such a position as to protect the knee from side impact. The lower edge of upper rear support 14 and the upper edge of lower rear support 16 are provided with approximately semi-circular cutouts, 15, 17 indicated by dotted lines, which allows added room for the foot and the leg to pass through the unit, so that the unit can be placed over the knee . Figure 2 shows upper and lower frontal supports 10, 12 as in Figure 1, and also an enlargement of part of lower support 12, and shows a left leg knee protector, in which the lower support 12 rotates anticlockwise with respect to the upper support 20. The upper support 10 is always held rigid because it is attached to the thigh. The hinging points to connect the supports 10, 12, 14, and 16 are in a slightly different arrangemant from those in Fig. 1. The extension 20 is shown separated from the support 12, to illustrate clearly the predeterminable relative rotation of the two parts. The upper edge of support 12 is formed as a J-shaped channel 46, of narrow bore 48 from the rear of the support towards the front, and of broader bore 50 around the front and to the rear of the support on the side distant from the viewer. The change of bore diameter occurs on the protector at a position corresponding to the inside of the human knee within it, and at an angle of about 45° in a horizontal plane from the front of the knee. Within the broader bore 50 adjacent the change to narrow bore 48 is a spring spacer (washer) 52, shown also in a partial, enlarged view. The extension 20 carries on its lower edge a J-shaped protrusion 54 having a narrow diameter part 56 and a broader diameter part 58. Figure 3 illustrates in section the J-shaped channel 46 and the J-shaped protrusion 54. Referring once more to Figure 2, the narrow end of 54 is inserted into the broad end of the channel 46 and the extension 20 is rotated clockwise relative to support 12 until it is in the same position in rotation relative to general support 12 as in the Figure. Further rotation is impossible because the broader diameter part 58 of protrusion 54 cannot enter the narrow bore part 48 of channel 46. The narrow diameter part 56 of J-protrusion 54 can however pass through " the spring spacer 52, but the spring spacer 52 itself cannot enter the narrow bore channel 48. When there is human knee within the protector, relative movement of the J-protrusion 54 in J-channel 46 permits the knee to rotate in a substantially horizontal plane. The maximum rotation permitted by the protector will be 45°. It is sometimes advantageous to limit such rotation, when for example the knee has been injured, or when the natural rotation of the knee is less than 45°. The permitted rotation can be set to the individual requirement of the person wearing the protector by adjusting the spring spacer 52 which can be held in position by placing a screw stud (not shown) through the broad bore part 50 of channel 46. This locks the spacer 52 in position and effectively increases the length of the narrower bore channel 48, and therefore limits rotational movement of J-shaped protrusion 54. The movement is the same as that of a human leg. If the knee is bent, the lower part of the leg (tibia) can be rotated while the upper part (thigh) is completely immobile. The stop 60 prevents the lower support from moving in the wrong direction, the lower right leg when bent does not rotate anticlockwise, lower left leg when bent does not rotate clockwise.Figure 2 shows a left knee protector, so the lower support 12 rotates anticlockwise in the same direction as the lower leg, and away from the stop 60. The stop 60 prevents movement of the lower support 12 inwards or clockwise, from the central position in which the edges of supports 20 and 12 are in line, as in the Figure. Figure 4 illustrates the arrangement which permits relative rotation of the upper and lower rear supports 14, 16. The lower support 16 has two upper, separable portions 62, 64, one on either side and each having an aperture 36, 66, for a stud (not shown). The upper edges of the support 16 adjacent the separable portions 62, 64 carry respective J-shaped channels 66, 68 and the lower edges of the separable portions 62, 64 carry J-shaped protrusions 70, 72. The J-protrusions run within the J-channels, as described with reference to Figures 2 and 3. The limitation of rotation is however predetermined solely by the frontal supports as illustrated in Figure 2. Figure 5 illustrates the frontal supports of a different embodiment of a knee protector having further, optional features. The protector comprises upper and lower frontal supports 80, 82 and a knee protector indicated generally at 84 which is formed by two overlapping parts 86, 88 hinged at 90, 92 to the upper and lower supports 80, 82 respectively. The two parts of the knee protector are hinged to each other at 94. Similar hinges are provided at the side of the protector remote from the viewer. The arrangement is such that the overlapping parts 86, 88 overlap by a varying amount in use, limited by the width of the sections 86 and 88. This gives the wearer greater mobility [in bending the knee] than the embodiment shown previously. A side impact protector, 96, shown spaced from the protector, may be hinged to the knee protector at hinges 94 and 92. Optionally, there can be placed within the knee protector a spacer 97 (shown largely by the dotted line) of resilient, friction-free material. The spacer can be fixed to the knee protector 94 at such a position that it cushions the anterior cruciate ligament of the knee. The spacer 97 can be of selected thickness, and such a spacer can be provided at each side of the knee to give a very close fit of the knee protector, giving good support of the anterior cruciate ligament. Such spacers can also be used with the embodiment of Figure 1, and in addition to ligament support can be used to give close fit of a protector to a knee. It is an advantage of a limb protector according to the invention that it can be individually adjusted to suit the joint it contains. For example, it may be manufactured in a number of basic sizes, which can be adjusted to fit the individual limb within it. Referring again to Figure 1, the frontal and rear supports may be fastened together by adjustable means, indicated schematically by the rectangles references 100, 102, 104, 106. The relative spacing of the frontal and rear supports can be individually varied to give a good fit. Preferably the adjustable means as such that the adjustment can be preset, and subsequent removal and replacement of the protector can be relatively rapid and simple. An example of such an adjustable means is shown in Figure 6. Figure 6(a) shows a ratchet 108 within a cover 110 which is spring loaded to prevent exposure of the ratchet and which retreats as the ratchet moves. There is a locking mechanism with a ring pull 114. Figure 6(b) shows an end view of Figure 6(a). Below the ring pull 114 there is a piston type mechanism 116 having an inverted T-shaped gap 118; when the ring pull is pulled, the gap 118 allows the ratchet 108 to run free within the cover 110. As spring retainer 120 returns the smaller gap of the inverted T-shape, which is shaped like a sawtooth so that when it is released, fits perfectly between the ratchet teeth, prevents the ratchet from moving back and forth, thus lacking the ratchet in place. The ratchet can therefore be adjusted to give the required separation of the frontal and rear supports for an individual leg. A torsion spring 112 then allows minimal expansion of the ratchet, to correspond to muscular expansion of the leg. In Figure 7, a method of adjusting the size of a knee protector is illustrated. The upper frontal support 10 is formed in two parts 10(a) and 10(b) with a vertical overlap 10(c) . The overlap on part 10(b) has two series of vertically-separated perforations, 124. The overlap on part 10(a) has a series of projecting studs 122 at the same distance as the perforations, and having right-angle ends which can enter the perforations. The amount of overlap is therefore adjustable, eg by 2 cm, and the size of the support 10 can be selected as appropriate. Figure 8 illustrates one of the studs which hinge the upper and lower, frontal and rear supports together. The stud 126 passes through the thickness of, for example, the lower rear support 16, lower frontal support 12, and knee protector 22. The head of the stud is protected by a cover cap 128 which is bullet- shaped to allow easy access of a split pin which is sandwiched between a spring washer 132 and a plain washer 134. The cover cap 128 is screwed into the top of the stud 126 and is prevented from coming undone by the spring washer 132. Figure 9 shows that any of the supports or knee protector can be made of a sandwich construction 136. Either in the inside of the sandwich contains a corrugated impact-absorbing material 138, or some other material is used that has relevant absorbtion coefficients. Figure 10 shows in assembled form a knee protector as illustrated in Figures 1 and 2. Supports 10, 12, 14, 16 and knee protector 22 are shown in their operative positions, together with side impact protector 41. Figure 11 shows how the same parts can be hinged to allow a wearer to place it on a knee, or remove it. Figure 12 shows a variation of a knee protector in which the upper and lower frontal supports 10(a), 12(a) are extended to give improved protection to the thigh and shin. In Figure 13, 13(a) is a view from the front of a knee protector and 13 (b) is a view from the rear of a knee protector. In Figure 13(a), the side impact protectors 40, 41 are connected to the knee protector 22 and other parts of the protector by studs 126. As will be seen, there are spacers 140 between the knee protector 22 and the side impact protectors 40, 41. There are also absorption pads 142 to take pressure from the side impact protectors 40, 41 when force is applied to them, to help distribute the impact force throughout the whole protector unit. Figure 13(b) also shows cutaway sections on the upper and lower rear supports which allow the wearers foot to pass through when the rear supports are hinged open as shown in Figure 11. Figure 13 (b) also illustrates the attachment points 146, 148 for an adjustable padded torsion bar (not shown) which can be locked to the protector behind the knee. This allows the protector to be used as a light weight temporary splint. A joint protector according to the invention allows free hinging of a joint such as a knee in the normal way, and predetermined rotational movement. In some circumstances however it may be advantageous to prevent rotational movement. Referring again to Figure 2, the main part of lower frontal support 12 carries an L-shaped projection 150 the female part of a coupling. Figure 14 shows a two-part knee protector as in Figure 5. Part 88 carries a male part of a coupling, 152 in the form of a square section rod. If the two parts of the coupling fit together, rotation of the protector is prevented. The two parts will be brought into this position when the wearer of the knee protector stands with a straight leg, and will uncouple when the wearer bends the knee. The lock thus works in a parallel way to the human leg. Figure 15 is a view of a two-part knee protector from inside, showing the two parts 86, 88, the hinge-points 90, 92, removable spacer 97 to protect the anterior cruciate ligament, and side impact protector 96 with its hinge points. Figure 16 is a schematic view of the protector of Figure 5, illustrating the hinge unit 94 which holds the two parts 86, 88, of the knee protector together. Figure 17 illustrates a variation of the knee protector shown in Figures 14 and 15, with the size adjustment device shown in Figure 7. The knee protector 140 has two overlapping part 142, 144, hinged together at hinge point 146 which has 3 hinge positions to allow adjustment to fit an individual knee. While the parts of the knee protector have been referred to as rigid, it is preferable to use a resilient material which by nature has impact-absorbing properties. Such a material is carbon fibre composite material. The spacers 97 are conveniently made of a softer material with relevant absorption coefficients, such as polypropylene. The inside of the knee protector may be line with a padding of stretch, anti-friction material, which may also extend to the insides of the upper and lower frontal supports. Such a lining allows the protector to move smoothly over the knee and helps to prevent pinching or damage to the kneecap. The invention has been described with reference to a knee protector, it is also applicable to an elbow protector.

Claims: CLAIMS 1. A limb protector comprises an upper rigid curved support; a lower rigid curved support; and means for permitting relative rotation of the upper support and the lower support. 2. A limb protector according to claim 1 in which the relative rotation take place in a plane substantially parallel to the planes of curvature of the upper and lower curved supports. 3. A limb protector according to claim 1 in which the amount of relative rotation is adjustable. 4. A limb protector according to claim 1 further comprising means to attach the upper and lower curved supports to a limb above and below a joint. 5. A limb protector according to claim 1 further comprising means for permitting relative hinging of the upper and lower supports in a plane orthogonal to the plane of relative rotation. 6. A limb protector according to claim 5 further comprising hinge-covering means to cover the abutment of the upper and lower supports during a hinging movement. 7. A limb protector according to claim 6 in which the hinge-covering means is provided in two parts connected to each other by hinge means. 8. A limb protector according to claim 1 in which the means for permitting relative rotation comprises an extension of one of the upper and lower supports between the upper and lower supports and rotatably connected to said support. 9. A limb protector according to claim 8 in which said extension is an extension of the lower support adjacent to the upper support. 10. A limb protector according to claim 1 in which the upper support comprises a curved frontal support and a curved rear support connected by hinge means, and the lower support comprises a curved frontal support and a curved rear support connected by hinge means. 11. A limb protector according to claim 10 further comprising hinge-covering means hinged to the upper and lower frontal supports. 12. A limb protector according to claim 1 further comprising a side impact protector exterior to and partially overlapping each of the upper and lower supports. 13. A limb protector according to claim 1 further comprising spacer means within and partially overlapping each of the upper and lower supports, the spacer means being of such a thickness that the limb protector is a close fit on a limb within it. 14. A limb protector according to claim 1 further comprising means to adjust the width and adjust the depth of the protector.

Inventors: DOYLE KELVIN CONRAD, DOYLE, KELVIN, CONRAD
Applicants: DOYLE KELVIN CONRAD, DOYLE, KELVIN, CONRAD
Application year: 1994
Main classification: A61F5
IPC codes: A61F5